There has been known an electronic control unit that controls motor operation. For example, the electronic control unit of JP2014-154745A includes a second metal plate exposed from a semiconductor module, a second specific shape part projecting from a radiator toward the semiconductor module, and a second heat conduction component sandwiched between the second metal plate and the second specific shape part.
When a radiating gel is disposed in the entire portion where a plurality of electronic components are provided while no partition exists between the electronic components, air may be incorporated into the radiating gel depending on a condition of the applied gel, degrading radiation performance. Moreover, it is necessary to design the application pattern or necessary to use a large amount of radiating gel not to cause the radiating gel to incorporate air.